A high-performance thermoacoustic refrigerator operating in room-temperature range

The working principle of an efficient travelling- wave thermoacoustic refrigerator operating in room-temperature range has been analyzed and an experimental set-up has been built. The experiment showed that suppressing DC-flow streaming was very critical to efficient operation, and an elastic membrane was used to solve the problem successfully. At the most efficient operating point, the novel thermoacoustic refrigerator achieved a cooling capacity of about 80 W at -20℃, with a much higher efficiency than previously developed standing-wave thermoacoustic refrigerator.     

In vivo Dynamic Studies of Brain Metabolism

Nuclear magnetic resonance （NMR） can noninvasively monitor intracellular concentrations and kinetic properties of numerous inorganic and organic compounds. A ^31p NMR surface coil was used in vivo to dynamically measure phosphocreatine （PCr）, adenosine triphosphate （ATP）, and intracellular inorganic phosphate （Pi） levels in mouse brain during ischemia-reperfusion to study the damage of cerebral tissues caused by ischemia and effects of herbs on cerebral energy metabolism during ischemia-reperfusion. The study provides dynamic brain energy metabolism data during different periods. The data show that some herbs more rapidly increase the PCr level during the recovery phase than in the control group.     

Application of microfluidic chip to realize controllable pH gradient

A kind of PH gradient microfluidic chips through soft-lithography microfabrication for isoelectric focusing (IEF) and high performance liquid chromatography (HPLC) is introduced here. These pH gradient chips have the advantages such as easy fabrication, controllable pH range and precision, isoelectric focusing and separation at the same time, low voltage for isoelectric focusing, and time stable pH gradient. This method has potential application to sample preparation, separation and analysis of microfluidic chips.     

光突发交换网络的数据信道分组抢占调度策略研究

光突发交换是面向下一代因特网的光交换模式,它结合了光电路交换和光分组交换的优点,同时克服了他们的一些缺点.介绍了光突发交换网络中一种支持区分服务的数据信道调度策略,通过仿真分析了数据信道分组策略对网络性能的影响,为进一步研究提供了有价值的参考.     

基于Web服务的网上书店开发

Web服务技术仍是一个新兴发展中的技术,然而无数迹象表明,Web服务将是未来应用架构的一个极 为重要的模式．随着Web服务的深入人心,会有越来越多的应用采用Web服务架构,开发Web服务的需求 将不断增加．     

Web服务技术及其应用

随着Web技术的发展,Web服务在网络中得到了广泛的应用．本文结合Web服务的发展需求,详细介 绍Web服务的含义和Web服务的应用分类．最后介绍Web服务的现状,并探讨Web服务的应用前景．     

Web服务的研究与开发

就网上书店如何实现Web服务问题进行了研究与分析,首先是对Web服务技术进行简单的介绍,其次 是对Web服务中所用到的协议进行简单的阐述,然后简述了Web Services的现状和实现过程．     

非法探取密码的原理及其防范

分析了在应用软件中使用Edit控件非法盗取密码的基本原理,给出了相应的技术防范措施．     

Web服务安全性分析

Web服务安全是当前焦点问题．文章利用协议栈介绍了Web服务的体系构架及其调用原理,详细分析了 Web服务安全性并提出一个解决的方案,在此基础上分析了Web服务的安全模型及其规范．     

基于基带预处理的连续相位(CPM)调制技术的研究

研究了两种基带IJF脉冲信号:双码元间隔升余弦脉冲以及双码元间隔三角脉冲,并对它们的性能参数 作了比较．利用基带预处理技术设计了一种性能优越的基带IJF信号码型,并将其应用于连续相位调制技术 中．仿真结果表明:与传统的调制技术相比,采用基带预处理技术脉冲形成的IJF-OQPSK调制技术,具有更 窄的主瓣宽度和更快的高频滚降速度,可在多种非线性场合下应用．